Device for lifting and handling objects

ABSTRACT

A device for lifting and handling objects, including cylindrical objects includes a lifting arm having a substantially vertical clamp portion and a substantially horizontal actuating portion provided with a lifting hook, a yoke having a substantially vertical clamp portion having ends and a substantially horizontal portion, the clamp portion of the lifting arm being, between its ends, pivotally connected to a free end of the substantially horizontal portion of the yoke, clamping jaws mounted on the clamp portions of the lifting arm and the yoke for engagement with diametrically opposite sides of an object to be lifted, a locking mechanism for releasably locking the lifting arm to the yoke in open position and a device for releasing the locking mechanism in downward swinging movement of the actuating portion of the lifting arm to allow the closing of the clamping jaws in order to grip the object to be lifted, the lifting hook being arranged for free movement in a slot provided in the actuating portion of the lifting arm and being connected to one end of a link, the link having an opposite end portion pivotally connected to the yoke remote from that end thereof which is pivotally connected to the clamp portion of the lifting arm.

This invention relates to a device for lifting and handling objects,especially cylindrical ones, comprising a lifting arm provided with alifting hook, which is pivotably attached to a yoke, oppositely directedclamping shoes being arranged on the lifting arm and on the yoke.

Devices for lifting different types of objects, e.g. bales, pipes, paperrolls, steel profiles, are previously known.

At such lifting devices using a clamping effect it is extremelyimportant that said clamping effect will not start to work before thelifting device is positioned. Moreover, the clamping effect shouldpreferably be released automatically or via remote control.

At a known device operating with clamping effect the clamping effect isreleased as the lifting hook is displaced laterally when the liftingdevice is positioned. This displacement can either take place from thedriver's stand of the crane or by a direct manual actuation of thelifting hook.

If said displacement is to take place from the driver's stand of thecrane a precision work is apparently concerned. If, on the other hand,manual displacement is to be used this seems to mean certain risks inrespect of labour safety as the displacement of the lifting hookreleases the locking mechanism of the pivoting of the lifting arm.

When lifting of an object is finished the locking mechanism is to bere-connected. One must then proceed in reversed manner to what has beendescribed above.

It is the object of this invention to show a device of the typementioned above, at which the release of the locking mechanism of thelifting arm takes place automatically or via remote control. Return tolocking of the lifting arm at a finished lifting operation takes placequite automatically.

The object of the invention is realized in that a device of the kindmentioned above has been given the characteristic features defined inthe appended claims.

An illustrative example of the invention will be described below withreference to the enclosed drawings, where

FIG. 1 is a lateral view of the device of the invention in a position toengage the object to be lifted;

FIG. 2 shows the device according to FIG. 1 in lifting position;

FIG. 3 shows a section taken on line III--III in FIG. 1;

FIG. 4 is a lateral view of an alternative embodiment of the device ofthe invention, the device being in a position to engage the object to belifted;

FIG. 5 is a lateral view of the device according to FIG. 4 in liftingposition and

FIG. 6 shows a section on the line VI--VI of FIG. 4.

The barrel lifting device shown in FIGS. 1 and 2 comprises an L-shapedlifting arm 1 which is pivotably connected via a joint 2 to an ear 3 ofa yoke 4. The lifting arm 1 is pivotable on the level of the paper inFIGS. 1 and 2.

At the free end of the stem of the arm there is arranged a lifting eye5. A clamping shoe 6 is disposed at the free end of the base portion ofthe arm.

A locking arm 7 is arranged on the lifting arm 1 somewhat above thejoint 2 via a joint 8. The locking arm 7 is pivotable on a levelparallel to the pivotal plane of the lifting arm 1 and provided with alocking shoulder 7a.

A release means 9 is pivotably arranged via a joint 10 on the lockingarm 7. The release means 9 is pivotable perpendicularly to the plane ofthe paper in FIGS. 1 and 2.

On the yoke 4 a sleeve 11 is adapted in which a pin 12 is movable in itslongitudinal direction. The pin 12 coacts with the release means 9 in away as will be described in detail below.

At its end facing away from the lifting arm 1 the yoke 4 has a fixedclamping shoe 13.

A counterweight container 14 is arranged at the end of the yoke 4 facingaway from the lifting arm 1. Balancing of the barrel lifting device iscarried out without a barrel and with the barrel lifting device in aposition according to FIG. 1. Liquid lead is thereafter filled into thecontainer 14 until the barrel lifting device enters a balance position.

In FIG. 3 the clamping shoes 6 and 13 are shown from above.

The contours of a barrel 15 are also drawn in FIGS. 1-3.

Using the barrel lifting device according to FIGS. 1-3 it is proceededin the following way.

The barrel lifting device enters the position shown in FIG. 1, where itis lowered downwards towards the barrel 15. As shown in FIG. 1 the pin12 will make contact with the upper side of the barrel. When the barrellifting device is further lowered the pin 12 will be displaced upwardsthrough the sleeve 11, the pin 12 displacing the release means 9upwards. When this displacement of the release means 9 has proceeded sofar that the shoulders 3a and 7a lose their engagement with each other,the lifting arm 1 will swing around the joint 2 and enter the positionshown in FIG. 2. As is apparent from FIG. 2 the two clamping shoes 6 and13 will then bear against the barrel 15. When a lifting force is appliedin the lifting ear 5 a torque will actuate the lifting arm 1 so that itswings around the joint 2, the clamping shoe 6 being pressed against thebarrel 15 which, in its turn, is pressed against the fixed clamping shoe13. The clamping effect produced by the lifting arm 1 onto the barrel 15is enough to lift the barrel 15 with a lifting force applied to thelifting eye 5.

After the barrel 15 is transferred to a desired place the barrel liftingdevice is to be released from the barrel 15.

In order that the barrel lifting device might release the barrel 15 therelease means 9 must be placed in such a position that it is notinfluenced by the movable pin 12. In practice this means that therelease means 9 is swung out from the lifting arm 1. When the pin 12makes contact with the barrel 15 and is displaced upwards it will passat the side of the release means 9 without displacing this.

At continued lowering of the lifting arm 1 towards the upper side of thebarrel 15 the locking shoulder 7a will engage the locking shoulder 3a.The clamping shoe 13 will then be moved away from the barrel 15 andenter the position according to FIG. 1. The lifting arm 1 is now lockedagainst pivoting around the joint 2, which means that if a lifting forceis applied to the lifting eye 5 the whole barrel lifting device will beraised from the barrel 15.

By returning the release means 9 to active position, i.e. it will beswung towards the lifting arm, the barrel lifting means is ready toengage a new barrel to be lifted.

The embodiment shown in FIGS. 4-6 comprises an L-shaped lifting arm 1',which is pivotable via a joint 2' to an ear 3' of a yoke 4'. The liftingarm 1' is pivotable on the level of the paper.

In the stem of the arm a slot 16 is made which extends from the free endof the stem to about half the height of the stem. A lifting eye 5' isfreely movable in the slot 16.

In a way corresponding to the embodiment according to FIGS. 1-3 there isarranged a locking arm 7' with a locking shoulder 7'a, which coacts witha locking shoulder 3'a of the ear 3'. A release means 9' operating in away corresponding to the release means 9 is arranged on the locking arm7'.

As in the embodiment according to FIGS. 1-3 a sleeve 11' is arranged onthe yoke 4', a pin 12' being movably received in the sleeve 11'.

On the yoke 4' in connection with the ear 3' there is arranged aremote-controlled electromagnet 17 which shows a displaceable piston17a. This electromagnet 17 can be activated from the driver's cab of thecrane supporting the barrel lifting device.

Two stays or links 18, one on each side of the yoke 4', extend from thefree end of the lifting arm 1 to a bolt 19 passing the yoke 4'. Thelinks 18 are guided by the bolt 19 via slots 20.

At the end of the yoke 4' facing away from the lifting arm 1' a fixedclamping shoe 13' is mounted.

In this connection it should be pointed out that the embodimentaccording to FIGS. 4-6 is lacking a counterweight.

The embodiment according to FIGS. 4-6 operates in the following way.

When the barrel lifting device is to be applied it is in the positionaccording to FIG. 4, i.e. the lifting arm 1 is locked against pivotingaround the joint 2'.

When lowering the barrel lifting device towards the barrel 15' the pin12' will make contact with the upper side of the barrel 15' and bedisplaced upwards through the sleeve 11' at further lowering of thebarrel lifting device towards the barrel 15'. At said displacement ofthe pin 12' it will make contact with the release means 9' and displacethis and the locking device 7' upwards. When the pin 12' has beendisplaced a predetermined way, the locking shoulders 3a and 7a will losetheir engagement with each other, the lifting arm 1' swinging around thejoint 2' to the position shown in FIG. 5. The clamping shoe 6' will thenbear against the barrel 15'.

When the free end of the lifting arm 1' moves upwards the lifting eye 5'will be displaced in the slot 16 towards the centre of the barrel 15'.This displacement takes place automatically as the slot 16 is inclinedupwards when the lifting arm 1' has entered the position according toFIG. 5. Thus, the lifting hook 5' will slide in the slot 16 when alifting force is applied to the lifting hook 5'. When the lifting hook5' has been displaced as far as the left end of the slot 16 in FIG. 5,lifting of the barrel 15' can be accomplished.

The embodiment according to FIGS. 4-6 also comprises an electromagnet 17with a movable piston 17a. By activation of this electromagnet 17 whichis made by means of remote control from the driver's cab, upwarddisplacement of the locking means 7' can be achieved, the lockingshoulders 3'a and 7'a losing their engagement with each other when thelocking arm 7' has been displaced a predetermined way. This displacementof the locking arm 7' produced by the electromagnet 17 thus correspondsto the displacement of the release means 9' caused by the pin 12'. Whenit is desired to use the electromagnet 17 for release of the engagementof the locking shoulders 3'a and 7'a, the release means 9' is swung toinactive position, i.e. the pin 12' can pass at the side of the releasemeans 9'.

After the electromagnet 17 has caused the engagement between the lockingshoulders 3'a and 7'a to cease, the piston 17a is pushed into theelectromagent 17 again.

When the barrel 15' has been moved to a desired place, the barrellifting device is to be released from the barrel 15'. In order that thismight be achieved it is required that the release means 9' is ininactive position.

The release of the barrel lifting device from the barrel 15' is carriedout in such a way that when the barrel 15' rests against the support andfurther lowering of the lifting arm 1' takes place, the locking shoulder7'a of the locking arm 7' will finally engage the locking shoulder 3'a.As the piston 17a is retracted and the release means 9' is in inactiveposition, these will not prevent the motion of the locking arm 7' toengagement with the locking shoulder 3'a. At the same time as thelocking arm 7' moves to the position according to FIG. 4 the rulers 18will displace the lifting hook 5' to the right in FIG. 4 to the endposition shown in FIG. 4. Now the barrel lifting device can be liftedfrom the barrel 15' and is then in balance. In should be pointed out inthis connection that the rulers 18 have no lifting function but theyonly guide the displacement of the lifting eye 5' in the slot 16.

The displacement of the lifting eye 5' described above will thus causethe barrel lifting device to be in balance at the position according toFIG. 4 without any counterweight being required.

Of course the barrel lifting device according to FIGS. 4-6 can beprovided with merely one electromagnet 17 which is remote-controlledfrom the driver's stand for release of the latch, i.e. the release means9', the sleeve 11' and the pin 12'. However, in practice it will be sothat the barrel lifting device is manufactured in a standard design withpin and sleeve and release means. The electromagnet can be obtained anextra accessories.

Of course the invention is by no means restricted to the illustrativeexamples described above but can be freely varied within the scope ofthe appended claims.

I claim:
 1. A device for lifting and handling objects, includingcylindrical objects, comprising a lifting arm having a substantiallyvertical clamp portion and a substantially horizontal actuating portionprovided with a lifting means, a yoke having a substantially verticalclamp portion having ends and a substantially horizontal portion, saidclamp portion of the lifting arm being, between its ends, pivotallyconnected to a free end of the substantially horizontal portion of theyoke, clamping jaws mounted on the clamp portions of the lifting arm andthe yoke for engagement with diametrically opposite sides of an objectto be lifted, a locking mechanism for releasably locking said liftingarm to the yoke in open position and means for releasing said lockingmechanism in downward swinging movement of the actuating portion of thelifting arm to allow the closing of the clamping jaws in order to gripthe object to be lifted, said lifting means being arranged for freemovement in a slot provided in the actuating portion of the lifting armand being connected to one end of a link means, said link means havingan opposite end portion pivotally connected to the yoke remote from thatend thereof which is pivotally connected to the clamp portion of thelifting arm.
 2. A device as in claim 1 wherein said opposite end portionof said link means is connected to said yoke by a bolt fixed to saidyoke, said bolt being received in a longitudinal slot in said linkmeans.